The present invention relates to a termite-controlling agent and a controlling method thereof.
Hitherto, various termite-controlling agents are known. Generally speaking, when pyrethroid compounds are used as a termite-controlling agent, they are not always satisfactory in the persistence of the efficacy in use for soil treatment, apart from that of the efficacy in use for wood treatment.
The present inventors have extensively studied to find a termite-controlling agent which is superior in the persistance of efficacy, and particularly effective also in use for soil treatment. As a result, the present inventors have found that a composition containing as active ingredients N-(2-ethylhexyl)bicyclo[2.2.1]hept-5-en-2,3-dicarboximide [MGK 264] and at least one pyrethroid compound selected from the group consisting of xcex1-cyano-3-phenoxy-benzyl-2-(4-chlorophenyl)-3-methylbutyrate [fenvalerate] and esters of 3-(2,2-dihalovinyl)-2,2-dimethylcyclo-propanecarboxylic acid with a 3-phenoxybenzyl alcohol which may have a cyano group at the xcex1-position (hereinafter this composition is referred to as present composition), is an excellent termite-controlling agent which can solve the above problem. The present inventors thus completed the present invention.
Among the pyrethroid compounds used in the present invention, fenvalerate has four optical isomers. Of these isomers, (S)-xcex1-cyano-3-phenoxybenzyl-(S)-2-(4-chloro-phenyl)-3-methylbutyrate [esfenvalerate] has the highest termite-controlling activity, so that a higher activity can be expected by using esfenvalerate itself or the isomer mixture containing an increased content of esfenvalerate.
The esters of 3-(2,2-dihalovinyl)-2,2-dimethylcyclopropanecarboxylic acid with 3-phenoxybenzyl alcohol which may have a cyano group at the xcex1-position include for example the following compounds:
3-phenoxybenzyl 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate [permethrin],
xcex1-cyano-3-phenoxybenzyl 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate [cypermethrin] and
(S)-xcex1-cyano-3-phenoxybenzyl d-cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropanecarboxylate [deltamethrin].
In the present composition, the weight ratio of the pyrethroid compound to MGK 264 is in the range of usually 1:1 to 1:20, preferably 1:2 to 1:8.
The present composition may contain a suitable carrier for formulation in addition to the pyrethroid compound and MGK 264. The proportion of the pyrethroid compound in the composition is usually 0.01 to 50 parts by weight, preferably 0.1 to 20 parts by weight. That of MGK 264 in the composition is usually 0.05 to 50 parts by weight, preferably 0.5 to 30 parts by weight.
The present composition may be formulated by the same method as used in formulation of common insecticides. For example, formulation is carried out as follows: The pyrethroid compound and MGK 264 are dissolved in an organic solvent such as aromatic hydrocarbons, aliphatic hydro-carbons, alicyclic hydrocarbons, alcohols, glycol esters, ketones and esters and if necessary, the resulting solution is fixed to a solid carrier by adsorption; and then auxiliaries for formulation such as emulsifiers, dispersing agents and wetting agents are added therein to formulate into emulsifiable concentrates, oil sprays, wettable powders, dusts, granules, suspension formulations, foaming formulations, spraying formulations, microcapsulated formulations and the like. Other active ingredients for killing termite, stabilizing agents, preservatives and the like may be incorporated into these preparations.
The present composition has a characteristic that it is effective also in use for soil treatment. The soil treatment is a method of forming a chemicals layer on a soil surface. More specifically, when the liquid formulation is applied, for example, to soil at the underfloor part that men can enter, of wood buildings, it is desirable to apply the liquid formulation with a power-driven sprayer, and particularly to chiefly treat the base of the buildings in which and paths are easily formed. When the liquid formulation is applied to soil at the underfloor part, that men cannot enter, of baths, entrances and the like, a method of making holes in the soil with a drill and injecting the liquid formulation into the holes, is employed.
The amount of the present composition used to control termite varies with treatment methods, preparation forms and other various conditions. Generally, however, the amount used in soil treatment is 1 to 100 g/m2, preferably 5 to 50 g/m2 in the total amount of the pyrethroid compound and MGK 264. In the case of wood treatment, the total amount is 0.1 to 10 g/m2, preferably 1 to 5 g/m2.